Methods and systems for charging an energy storage device

ABSTRACT

A charging device for charging an energy storage device is described. The charging device includes a memory for storing a plurality of state machines and a processing device coupled to the memory. The processing device is configured to select a state machine of the plurality of state machines and to operate the charging device in accordance with the selected state machine.

BACKGROUND OF THE INVENTION

The embodiments described herein relate generally to electric vehiclesand, more specifically, to methods and systems for charging a vehiclethat includes an electrochemical energy storage device.

In response to both increasing fuel costs related to the use ofconventional combustion engine vehicles and heightened environmentalconcerns, including air pollution, the use of electric and hybridvehicles has increased. As a result, energy demand will likely increasein the form of electrical energy used to charge batteries or otherenergy storage devices used in such vehicles. Electric vehicles, orvehicles that include an electrochemical energy storage device, aredefined herein as vehicles that derive some portion of the power used topropel the vehicle from an energy storage device, for example, frombatteries. Electric vehicles may include, but are not limited to,vehicles that rely solely on energy stored in batteries to drive anelectric motor that propels the vehicle (e.g., a traction motor),vehicles that include batteries for storing energy used to drive atraction motor and also include an internal combustion engine thatdrives a generator used to recharge the batteries, and vehicles thatinclude a combination of electric and fossil fuel powered components(e.g., hybrid vehicles).

Currently, charging devices, also referred to as charging stations orelectric vehicle supply equipment (EVSE), provide power to an electricvehicle for charging of the energy storage devices within the electricvehicle. However, safety requirements and charging protocols are notconsistent throughout the world. The various requirements and protocolsmay necessitate that a different model of charging station controller bedesigned and manufactured for use in different parts of the world.

BRIEF DESCRIPTION OF THE INVENTION

In one aspect, a charging device for charging an energy storage deviceis provided. The charging device includes a memory for storing aplurality of state machines and a processing device coupled to thememory. The processing device is configured to select a state machine ofthe plurality of state machines and to operate the charging device inaccordance with the selected state machine.

In another aspect, a method for controlling a charging device forcharging of an energy storage device is provided. The method includesstoring a plurality of state machines and configuring a charging devicecontroller to select a state machine of the plurality of state machinesand to operate the charging device in accordance with the selected statemachine.

In yet another aspect, a system for charging an energy storage device isprovided. The system includes a memory for storing a plurality of statemachines and a processing device coupled to the memory. The processingdevice is configured to select a state machine of the plurality of statemachines and to operate the system in accordance with the selected statemachine.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of an exemplary charging station controllerincluded within an exemplary electric vehicle charging station.

FIG. 2 is a block diagram of the charging station controller shown inFIG. 1, included within, and configured to control operation of, analternative electric vehicle charging station.

FIG. 3 is an exemplary embodiment of a first state machine stored withinthe charging station controller shown in FIG. 1.

FIG. 4 is an exemplary embodiment of a second state machine storedwithin the charging station controller shown in FIG. 1.

FIG. 5 is an exemplary embodiment of a third state machine stored withinthe charging station controller shown in FIG. 1.

FIG. 6 is an exemplary embodiment of a fourth state machine storedwithin the charging station controller shown in FIG. 1.

FIG. 7 is a flow chart of an exemplary method for controlling anelectric vehicle charging station.

DETAILED DESCRIPTION OF THE INVENTION

The methods and systems described herein facilitate charging an energystorage device. More specifically, the methods and systems describedherein facilitate charging of a vehicle that includes an electrochemicalenergy storage device. Furthermore, the methods and systems describedherein facilitate use of a single electric vehicle charging devicecontroller in various models of electric vehicle charging devices, alsoreferred to herein as electric vehicle charging stations. Such modelsmay be required to adhere to standards and/or protocols specific to acountry and/or region where the charging station is to be operated. Thecharging station controller is configured to operate in accordance witha plurality of state machines, wherein each state machine corresponds toa different model of electric vehicle charging station.

Technical effects of the methods and systems described herein include atleast one of: (a) storing a plurality of state machines; (b)initializing an electric vehicle charging station; (c) determining aselected state machine of the plurality of state machines; and (d)operating the electric vehicle charging station in accordance with theselected state machine.

FIG. 1 is a block diagram of an exemplary charging station controller 10included within an exemplary electric vehicle charging station 12. Inthe exemplary embodiment, charging station controller 10 is amicrocontroller that includes a processing device 14 and a memory 16.The term controller, as used herein, may refer to central processingunits, microprocessors, microcontrollers, reduced instruction setcircuits (RISC), application specific integrated circuits (ASIC), logiccircuits, and any other circuit or processor capable of executing thefunctions described herein.

In the exemplary embodiment, charging station 12 is configured foroperation at a first location. For example, charging station 12 isconfigured to operate in accordance with standards promulgated forcharging station operation at the first location. More specifically,various standards and/or regulations regarding charging of an electricvehicle are implemented in different countries and/or in differentregions of the world. For example, a charging station operated in theUnited States of America must satisfy different regulatory standardsthan a charging station operated in Germany. Current standards forcharging stations operated in the United States of America may bereferred to as National Electrical Manufacturers Association (NEMA)compliant standards. For example, a NEMA compliant charging station iscompliant with Society of Automotive Engineers (SAE) standards,including, but not limited to SAE standard J1772 for vehicle chargingfunctionality, and Underwriters Laboratories (UL) standards, includingbut not limited to, UL standard 2231 for protection functionality.Current standards for charging stations operated in Europe are publishedby the International Electrotechnical Commission (IEC), for example, inIEC standard 61851. In the exemplary embodiment, charging station 12 isconfigured for NEMA compliant charging of an electric vehicle 22.

In the exemplary embodiment, electric vehicle charging station 12includes at least one input connector 50 for coupling with an AC powersource 52. For example, AC power source 52 may include, but is notlimited to, an AC grid. Input connector 50 may include a plurality ofterminals configured to place charging station 12 in electricalcommunication with AC power source 52, components that facilitateinductive coupling of charging station 12 and AC power source 52, and/orany other type of connector that places charging station 12 inelectromagnetic communication with AC power source 52. AC grids aremaintained at different voltage levels dependent upon a location withinthe distribution/transmission process. In the exemplary embodiment, ACpower source 52 provides charging station 12 with 240 volt single phaseAC power, which is a typical voltage level available on a power gridlocated in the United States of America. Although described as receiving240 volt AC power, charging station 12 may receive power having anysuitable voltage level that allows the charging station 12 to functionas described herein.

In the example embodiment, electric vehicle charging station 12 alsoincludes a plurality of conductors, for example, positioned within anelectrical cable 60. In the example embodiment, electrical cable 60includes an output connector 62 and electric vehicle 22 includes acorresponding input connector, included within, for example, aconnection device 64, for coupling charging station 12 to electricvehicle 22. Output connector 62 may include a plurality of terminalsconfigured to place charging station 12 in electrical communication withelectric vehicle 22, components that facilitate inductive coupling ofcharging station 12 and electric vehicle 22, and/or any other type ofconnector that selectively places charging station 12 in electromagneticcommunication with electric vehicle 22.

In the exemplary embodiment, charging station 12 includes a ground faulttesting device 66 coupled to controller 10. Ground fault testing device66 may include, but is not limited to, a ground fault currenttransformer. If ground fault testing device 66 detects a ground faultcondition, controller 10 registers a fault condition.

In the exemplary embodiment, charging station 12 also includes aconnector sensor 70. Controller 10 determines if output connector 62 hasbeen returned to charging station 12 based on a signal from connectorsensor 70. Output connector 62 is returned to charging station 12 in asimilar manner to a nozzle being returned to a gasoline pump.

Charging station 12 also may include at least one display device 72communicatively coupled to controller 10. For example, display device 72may be in electrical communication with controller 10, may be configuredto wirelessly communicate with controller 10, and/or may be incommunication with controller 10 in any other manner that allowscharging station 12 to function as described herein. Controller 10 isconfigured to provide information to an operator of charging station 12using display device 72 and/or to prompt the operator to provideinformation to charging station 12. For example, display device 72 mayinclude a light emitting diode (LED) bar 74 and/or a vacuum fluorescentdisplay (VFD) 76. Display device 72 may also include, but is not limitedto, a liquid crystal display (LCD) and/or an LED display.

Furthermore, in an alternative embodiment, display device 72 is notincluded within charging station 12, but rather, is positioned remotelyfrom charging station 12 and communicatively coupled to charging station12. For example, if charging station 12 is positioned outside, forexample, in a parking facility, display device 72 may be included withina kiosk positioned inside a structure. This would allow a user tointeract with charging station 12 while protected from the elements. Inanother example, display device 72 may be included within a consumerdevice capable of receiving information from charging station 12.Display device 72 may be included within a cellular communicationsdevice and/or a personal computer configured to receive, for example, ashort message service (SMS) text message or electronic mail message fromcharging station 12. Furthermore, display device 72 may be includedwithin a consumer device capable of accessing a World Wide Web site thatincludes information provided by charging station 12. In the alternativeembodiment, charging station 12 also includes a communication device 77that transmits information, for example, to an external server (e.g., abackend server), which either provides the consumer device with accessto the information, or transmits the information to the consumer device.Furthermore, communication device 77 may also be configured to receiveinformation from such a kiosk or consumer device, including, but notlimited to, an operator's response to a prompt for information fromcharging station 12.

Charging station 12 may also include at least one authorization device78. Authorization device 78 may include, but is not limited to, akeypad, a radio frequency identification (RFID) device, a magneticstripe card reader, and a biometrics reader. Authorization device 78provides controller 10 with authentication information identifying, forexample, an identity of an operator of electric vehicle 22, a make/modelof electric vehicle 22, and/or a financial account associated with theoperator of electric vehicle 22. In the exemplary embodiment, controller10 may compare the authentication information to data stored in aninternal database to authorize the operator, or may transmit theauthentication information to a server positioned external to chargingstation 12 for off-site authorization of the operator.

In an alternative embodiment, authorization device 78 is not includedwithin charging station 12, but rather, is positioned remotely from, andcommunicatively coupled to, charging station 12. As described above withrespect to display device 72, authorization device 78 may be includedwithin, as examples only, a kiosk or a consumer device capable ofreceiving information from, and transmitting information to, chargingstation 12. For example, a cellular communications device and/or apersonal computer may be used to provide charging station 12 withauthentication information.

In the exemplary embodiment, controller 10 includes a plurality of statemachines. For example, the plurality of state machines may be stored infirmware included within controller 10. Controller 10 operates inaccordance with a selected one of the state machines. As referred toherein, a state machine is a behavioral model composed of states andtransitions between the states that are enabled by fulfillment of atleast one predefined condition, for example, a change to an input to thesystem monitored by the state machine. Entry, waiting to exit, and exitactions are executed for each state. For example, the state machineresponds to an input to the system by transitioning out of a first state(i.e., a current state) and entering a second state. The state machineexecutes exit actions associated with the first state upon exiting thefirst state and executes entry actions associated with the second stateupon entering the second state. After entering the second state, thestate machine also executes waiting to exit actions associated with thesecond state until the inputs change and trigger another statetransition.

In the exemplary embodiment, controller 10 may include a state machineconfigured such that controller 10 operates in accordance with therequirements of the first location, for example, in accordance with NEMAstandards. Controller 10 may also include a state machine configuredsuch that controller 10 operates in accordance with requirements of aspecific purchaser of charging station 12 and/or in accordance withspecifications of a specific model of charging station 12. For example,operating in accordance with a first state machine configures controller10 to analyze inputs from devices including, but not limited to, groundfault testing device 66 and connector sensor 70, and to operate chargingstation 12 in accordance with NEMA standards.

More specifically, each of the state machines manages a sequence ofevents and actions that charging station 12 performs to run a chargecycle. Each state machine includes a list of states that chargingstation 12 may enter when interfacing with an operator and/or a vehicle.Furthermore, each state machine includes entry actions and exit actionsassociated with each state as well as waiting actions that are executedwhile waiting to transition out of the state. In order to meet a firstplurality of requirements, charging station 12 performs predefined testsprior to commencing a charging session. There are also tests andnotifications that are issued to achieve design and performance goals.The state machine also enables controller 10 to be responsive to avehicle pilot signal and to provide user feedback via display device 72.

In the exemplary embodiment, after initialization of charging station12, firmware included within controller 10 determines which statemachine of the plurality of state machines to run. In the exemplaryembodiment, charging station 12 includes an input interface 80 forreceiving a charging station selection signal. For example, controller10 may determine which state machine to run based on the chargingstation selection signal received via input interface 80. For example,when installing charging station 12, a technician may select one statemachine that controller 10 should run. Input interface 80 may include,but is not limited to including, at least one dual in-line package (DIP)switch, a connector configured to receive one of a plurality of wiringharnesses, a communication device configured to receive a chargingstation selection signal, and/or or any other suitable type of inputdevice that allows charging station 12 to function as described herein.More specifically, the communication device may include or be coupled toa configuration server that provides settings to a non-volatile memory(e.g., memory 16) for storage in the non-volatile memory. In analternative embodiment, controller 10 determines which state machine torun based on a detected configuration of charging station 12.

By configuring controller 10 to operate in accordance with a statemachine, and by storing a plurality of state machines within controller10, a single controller may be designed and manufactured for use in avariety of charging station models. Furthermore, an identical controller10 may be included within charging stations having a variety ofdifferent features, and/or a variety of different feature packages. Asnew charging station model options are offered by a manufacturer,additional state machines may be included within controller 10. As newfeatures are offered for use by a specific model of charging station 12,new or edited states may be added to state machines stored withincontroller 10.

Furthermore, charging station 12 may include a power meter 82, whichalso may be referred to as a smart meter. Power meter 82 monitors andcontrols an output of charging station 12. For example, power meter 82may limit the power output of charging station 12.

In the exemplary embodiment, electric vehicle 22 includes an electricmotor 90 and at least one energy storage device, for example, but notlimited to, a battery 92 configured to power electric motor 90. Electricmotor 90 is coupled to a traction system (not shown in FIG. 1) ofelectric vehicle 22 and may also be referred to as a traction motor.Battery 92, as referred to herein, may include a single electrochemicalcell, a plurality of electrochemical cells coupled to form a batteryarray, or any other suitable configuration of chemical energy storagedevices.

Electric vehicle 22 also includes a system controller 94 configured tocommunicate with controller 10. System controller 94 and chargingstation controller 10 control a pilot signal used for communicationbetween electric vehicle 22 and controller 10. For example, chargingstation controller 10 may control whether the pilot signal is constantor oscillating and system controller 94 may control a magnitude of thepilot signal to indicate if vehicle 22 is connected, ready to charge,and/or ready to charge with a vent fan. More specifically, when electricvehicle 22 is coupled to charging station 12, system controller 94 maydrive the pilot signal down from a constant 12 volts (V) to 9 V. Whencharging begins, charging station controller 10 may oscillate the signalto indicate to system controller 94 a level of current vehicle 22 maydraw (e.g., a duty cycle of the oscillating signal corresponds to thecurrent level). Control of the pilot signal is based on predefinedstandards, for example, Society of Automotive Engineers (SAE) standardJ1772.

FIG. 2 is a block diagram of charging station controller 10 includedwithin, and configured to control operation of, an alternative electricvehicle charging station 100. The alternative electric vehicle chargingstation 100 is configured for operation at a second location. Forexample, charging station 100 is configured to operate in accordancewith standards promulgated for charging station operation at the secondlocation. In the alternative embodiment, charging station 100 isconfigured for IEC compliant charging of an electric vehicle 22. Morespecifically, charging station controller 10 is configured for operationin the second location.

In the exemplary embodiment, charging station 100 is coupled to, andconfigured to receive power from, AC power source 52. AC power source 52may provide charging station 100 with 380 volt 3-phase AC power, whichis a typical voltage level available on a power grid located in, forexample, European countries. Although described as receiving 380 volt ACpower, charging station 100 may receive power having any suitablevoltage level that allows the charging station 100 to function asdescribed herein.

One example difference between a NEMA compliant charging station and anIEC compliant charging station is the detection of a ground fault. NEMAspecifications include use of a ground fault testing device 66 (shown inFIG. 1), for example, a ground fault current transformer. In contrast,electric vehicle charging station 100 includes a residual currentdetection device (RCD) 110. Controller 10 identifies a level of residualcurrent based on a signal from RCD 110 and registers a fault if thelevel is above a predefined level. For example, the predefined level isdefined within IEC standards.

Charging station 100 may also include a locking mechanism 112 that locksa cable 114 to charging station 100. An example of locking mechanism 112is available from Mennekes® Electrical Products of Fairfield, N.J., USA.In contrast to the NEMA compliant charging station 12 (shown in FIG. 1),charging station 100 does not include a cable for selectively couplingcharging station 100 to electric vehicle 22. Rather, cable 114 isprovided by the operator of electric vehicle 22. Charging station 100includes an output connector 116 and locking mechanism 112 that couplewith a first end 120 of cable 114. A second end 122 of cable 114 isconfigured for coupling with electric vehicle 22. Output connector 116may include a plurality of terminals configured to place chargingstation 100 in electrical communication with electric vehicle 22,components that facilitate inductive coupling of charging station 100and electric vehicle 22, and/or any other type of connector thatselectively places charging station 100 in electromagnetic communicationwith electric vehicle 22. Since cable 114 is provided by the operator,controller 10 and locking mechanism 112 prevent unauthorized removal ofcable 114 from charging station 100 during charging.

As described with respect to charging station 12, charging station 100may also include authorization device 78. Furthermore, controller 10includes a plurality of state machines. Controller 10 operates inaccordance with a selected one of the plurality of state machines. Forexample, controller 10 may include a state machine configured such thatcontroller 10 operates in accordance with the requirements of the secondlocation, for example, in accordance with IEC standards. For example,controller 10 is configured to receive inputs from devices including,but not limited to, RCD 110 and locking mechanism 112, and operatecharging station 100 in accordance with IEC standards.

FIG. 3 is an exemplary embodiment of a first state machine 200 storedwithin controller 10 (shown in FIG. 1). In the exemplary embodiment,first state machine 200 corresponds to NEMA compliant operation ofcontroller 10. More specifically, controller 10, when instructed tooperate in accordance with first state machine 200, will controloperation of charging station 12 (shown in FIG. 1) in compliance withNEMA standards.

In the exemplary embodiment, when charging station 12 is idle, statemachine 200 is in a connection pending state 220 waiting for a user toconnect a vehicle, for example, vehicle 22 (shown in FIG. 1), tocharging station 12. From connection pending state 220, state machine200 may transition to a smart meter interface state 222, a hard/servicefault state 224, a soft fault state 226, or an alarm state 228. Whenvehicle 22 is connected to charging station 12 and no faults/alarms aredetected, state machine 200 transitions from connection pending state220 to smart meter interface state 222. Exit criteria for exitingconnection pending state 220 may include, but is not limited to, adetermination that vehicle 22 is coupled to charging station 12 and thatno faults are detected. Once entering a new state, state machine 200runs all associated entry and waiting actions for that state whilewaiting for the exit criteria to be satisfied.

For example, entry actions for smart meter interface state 222 mayinclude, but are not limited to, driving LED bar 74 (shown in FIGS. 1)to indicate that vehicle 22 is connected, requesting authorization froma smart meter, for example, smart meter 82 (shown in FIG. 1), andpassively updating user display 76 (shown in FIG. 1) based on thecurrent state. Examples of wait actions for smart meter interface state222 include, but are not limited to, waiting for smart meterauthorization and timing out if no response is received from smart meter82. When vehicle 22 is connected to charging station 12, nofaults/alarms are detected in the system, and after receipt ofauthorization from smart meter 82, or after timing out if no response isreceived, state machine 200 transitions into a ground fault test state240. State machine 200 transitions out of ground fault test state 240and into a pilot test state 244 when vehicle 22 is connected to chargingstation 12, no faults/alarms are detected in the system, and a groundfault test is passed. For example, controller 10 bases the ground faulttest on a signal received from ground fault testing device 66 (shown inFIG. 1).

State machine 200 transitions out of pilot test state 244 and into avehicle ready pending approval state 246 when vehicle 22 is connected tocharging station 12, no faults/alarms are detected, the ground faulttest is passed, and the pilot test is passed. State machine 200transitions out of vehicle ready pending approval state 246 and into acharging state 250 when vehicle 22 is connected to charging station 12,no faults/alarms are detected, the ground fault test is passed, thepilot test is passed, and a charge signal is received, for example, fromthe operator of vehicle 22 and/or from system controller 94 via thepilot signal. When vehicle 22 discontinues sending the charge signal,state machine 200 transitions to an end state 252. Not receiving thecharge signal from vehicle 22 indicates to charging station 12 thatvehicle 22 is not requesting power from charging station 12. Statemachine 200 may transition back to charging state 250 if the chargesignal is received at controller 10 while in end state 252.

State machine 200 also transitions out of end state 252 to a returnconnector state 254 when no faults/alarms are detected and outputconnector 62 (shown in FIG. 1) is removed from vehicle 22. Moreover,state machine 200 transitions out of return connector state 254 toconnection pending state 220 when no faults/alarms are detected andeither connector 62 is returned to charging station 12 or connector 62is not returned to charging station 12 and a predefined time limit isexceeded.

State machine 200 may enter hard/service fault state 224, soft faultstate 226, and alarm state 228 from any other state. To exit a state,controller 10 checks if any faults/alarms are detected in the system.For example, all states (other than connection pending state 220 andhard/service fault state 224) exit to end state 252 when vehicle 22 isdisconnected. Similarly, state machine 200 transitions from any state tohard/service fault state 224 when controller 10 detects a hard/servicefault. State machine 200 transitions from any state (other thanhard/service fault state 224) to soft fault state 226 when controller 10detects a soft fault. State machine 200 transitions from any state(other than hard/service fault state 224 and soft fault state 226) toalarm state 228 when controller 10 detects an alarm. State machine 200will exit soft fault state 226 when connector 62 is disconnected fromvehicle 22. Once connector 62 is disconnected from vehicle 22, statemachine 200 will transition from soft fault state 226 to end state 252.In contrast, state machine 200 will exit hard/service fault state 224only when charging station 12 is disconnected from power source 52(shown in FIG. 1), charging station 12 is serviced, and power isreturned to charging station 12.

Examples of hard/service faults include, but are not limited to, a pilotsignal outside of a predefined range at power up, improper controlconfiguration, a contactor that is welded closed, a corrupt non-volatilememory, a measured temperature outside of a predefined range, acontroller error, and an invalid media access control (MAC) address.

Examples of soft faults include, but are not limited to, a ground faultsensor self-test failure, an over current trip, a pilot diode self-testfailure, a contactor not closing, and receipt of a request for vent fancharging when the charging station is not configured to support suchcharging.

Examples of alarms include, but are not limited to, a detected groundfault, an engaged E-Stop, a pilot signal that violates an expectedtransition, a grounded pilot signal, a detected over voltage, a detectedunder voltage, and a signal from a smart meter that disables charging.

FIG. 4 is an exemplary embodiment of a second state machine 300 storedwithin controller 10 (shown in FIG. 2). In the exemplary embodiment,second state machine 300 corresponds to IEC compliant operation ofcontroller 10. More specifically, controller 10, when instructed tooperate in accordance with second state machine 300, will controloperation of charging station 100 (shown in FIG. 2) in compliance withIEC standards.

In the exemplary embodiment, when charging station 100 is idle, statemachine 300 is in a connection pending state 320 waiting for a user toconnect a vehicle, for example, vehicle 22 (shown in FIG. 1), tocharging station 100. From connection pending state 320, state machine300 transitions to a plug lock state 322 when vehicle 22 is connected tocharging station 100 and no faults/alarms are detected. As describedabove, charging station 100 includes a locking mechanism 112 for lockingcable 114 to charging station 100. State machine 300 transitions fromplug lock state 322 to a smart meter interface state 324 when vehicle 22is connected to charging station 100, no faults/alarms are detected, andlocking mechanism 112 is activated to lock cable 114 to charging station100.

Entry actions for smart meter interface state 324 may include, but arenot limited to, driving LED bar 74 (shown in FIG. 2) to indicate thatvehicle 22 is connected, requesting authorization from smart meter 82before proceeding, and passively updating user display 76 (shown in FIG.2) based on the current state. Examples of wait actions for smart meterinterface state 324 include, but are not limited to, waiting for smartmeter authorization and timing out if no response is received from smartmeter 82.

When vehicle 22 is connected to charging station 100, no faults/alarmsare detected, and after receipt of authorization from smart meter 82, orafter timing out if no response is received from smart meter 82, statemachine 300 transitions into a pilot test state 330. State machine 300transitions out of pilot test state 330 and into a vehicle ready pendingapproval state 332 when vehicle 22 is connected to charging station 100,no faults/alarms are detected, locking mechanism 112 is activated tolock cable 114 to charging station 100, and the pilot test is passed.State machine 300 transitions out of vehicle ready pending approvalstate 332 and into a charging state 350 when vehicle 22 is connected tocharging station 100, no faults/alarms are present in the system,locking mechanism 112 is activated to lock cable 114 to charging station100, the pilot test is passed, and a charge signal is received, forexample, from the operator of vehicle 22 and/or from system controller94 via the pilot signal. When vehicle 22 discontinues sending the chargesignal, state machine 300 transitions to an end state 352. Not receivingthe charge signal from vehicle 22 indicates to charging station 100 thatvehicle 22 is not requesting additional power from charging station 100.State machine 300 may transition back to charging state 350 if thecharge signal is received at controller 10 while in end state 352.

State machine 300 also transitions out of end state 352 to a plug unlockstate 354 when no faults/alarms are detected. In plug unlock state 354,controller 10 unlocks output connector 62 from charging station 100.State machine 300 may transition from plug unlock state 354 to a userprompt state 356 where controller 10, via LED bar 74 (shown in FIG. 2),instructs the user to remove cable 114 from charging station 100.Moreover, state machine 300 transitions out of user prompt state 356 toconnection pending state 320 when no faults/alarms are detected andeither cable 114 is disconnected from charging station 100 or if cable114 is not removed from charging station 100 and a predefined time limitis exceeded.

State machine 300 also includes a soft fault state 360, a hard/servicefault state 362, and an alarm state 364. State machine 300 may entersoft fault state 360, hard/service fault state 362, and alarm state 364from any other state. To exit a state, controller 10 checks if anyfaults/alarms are present in the system. For example, all states (otherthan connection pending state 320 and hard/service fault state 362) exitto the end state 352 when vehicle 22 is disconnected from chargingstation 100. Similarly, state machine 300 transitions from any state tohard/service fault state 362 when controller 10 detects a hard/servicefault. State machine 300 transitions from any state (other thanhard/service fault state 362) to soft fault state 360 when controller 10detects a soft fault. State machine 300 transitions from any state(other than hard/service fault state 362 and soft fault state 360) toalarm state 364 when controller 10 detects an alarm. State machine 300will exit soft fault state 360 when connector 62 is disconnected fromvehicle 22. Once disconnected, state machine 300 will transition fromsoft fault state 360 to end state 352. In contrast, state machine 300will exit hard/service fault state 362 only when charging station 100 isdisconnected from power source 52 (shown in FIG. 1), charging station100 is serviced, and power is returned to charging station 100.Furthermore, to facilitate allowing a user to remove cable 114 fromcharging station 100, after occurrence of a hard/service fault, statemachine transitions from hard/service fault state 362 to plug unlockstate 354. Once cable 114 is removed from charging station 100, statemachine 300 returns to hard/service fault state 362 until power isremoved from charging station 100, charging station 100 is serviced, andpower to charging station 100 is restored.

In contrast to state machine 200, state machine 300 does not include aground fault testing state. Rather, and due to the hardware differencesbetween NEMA charging station 12 and IEC charging station 100, ifcontroller 10 determines the residual current is above the predefinedlevel, based on a signal from RCD 110 (shown in FIG. 2), state machine300 enters soft fault state 360.

FIG. 5 is an exemplary embodiment of a third state machine 400 storedwithin controller 10 (shown in FIG. 1). In the exemplary embodiment,third state machine 400 corresponds to NEMA compliant operation ofcontroller 10 in a charging station that includes an authorizationdevice, for example, authorization device 78 (shown in FIG. 1). Morespecifically, controller 10, when instructed to operate in accordancewith third state machine 400, will control operation of charging station12 (shown in FIG. 1) in compliance with NEMA standards and only providepower to vehicle 22 after receiving proper authorization.

State machine 400 includes an idle state 410 where controller 10 waitsto receive an authorization input from a user. State machine 400transitions from idle state 410 to an authorization state 412 whencontroller 10 receives an authorization input from a user, for example,via authorization device 78. If the authorization is approved, statemachine 400 transitions to a vehicle connection pending state 414. Statemachine 400 transitions from vehicle connection pending state 414 to asmart meter interface state 222 when vehicle 22 is connected to chargingstation 12, no faults/alarms are detected, and authorization isapproved.

If the authorization is denied, state machine 400 enters anauthorization denied state 418. If the authorization input is receivedagain, state machine 400 returns to authorization state 412 to determineif the authentication is approved. If the authorization input is notreceived again, state machine transitions to return connector state 254after a predefined time limit is exceeded.

Alternatively, if output connector 62 is connected to vehicle 22 whenstate machine 400 is in idle state 410, state machine 400 enters vehicleconnected/waiting for authorization input state 420. If authorization isapproved and no faults/alarms are detected, state machine 400transitions to smart meter interface state 222.

FIG. 6 is an exemplary embodiment of a fourth state machine 500 storedwithin controller 10 (shown in FIG. 1). In the exemplary embodiment,fourth state machine 500 corresponds to IEC compliant operation ofcontroller 10 in a charging station that includes an authorizationdevice, for example, authorization device 78 (shown in FIG. 2). Morespecifically, controller 10, when instructed to operate in accordancewith fourth state machine 500, will control operation of chargingstation 100 (shown in FIG. 2) in compliance with IEC standards and onlyprovide power to vehicle 22 after receiving proper authorization.

State machine 500 includes authorization states both for receivingpermission to charge a vehicle using charging station 100 and forreceiving permission to unlock cable 114 from charging station 100. Forexample, state machine 500 includes an idle state 510 where controller10 waits to receive an authorization input from a user. State machine500 transitions from idle state 510 to an authorization state 512 whencontroller 10 receives an authorization input from a user, for example,via authorization device 78. If the authorization is approved, statemachine 500 transitions to a vehicle connection pending state 514. Statemachine 500 transitions from vehicle connection pending state 514 toplug lock state 322 when vehicle 22 is connected to charging station100, no faults/alarms are detected, and authorization is approved.

If the authorization is denied, state machine 500 enters anauthorization denied state 518. If the authorization input is receivedagain, state machine 500 returns to authorization state 512 to determineif the authentication is approved. If the authorization input is notreceived again, state machine transitions to remove user prompt state356 after a predefined time limit is exceeded.

Alternatively, if vehicle 22 is coupled to charging station 100 whenstate machine 500 is in idle state 510, state machine 500 enters vehicleconnected/waiting for authorization input state 520. If authorization isapproved and no faults/alarms are detected, state machine 500transitions to plug lock state 322.

To ensure that only an authorized user uncouples cable 114 from chargingstation 100, state machine 500 may transition from end state 352 to anauthorization state 530. Controller 10 receives an authorization inputvia authorization device 78, and if approved, transitions fromauthorization state 530 to unlock plug state 354. If the authorizationinput is denied, state machine 500 transitions back to authorizationstate 530.

FIG. 7 is a flow chart 550 of an exemplary method 552 for controlling anelectric vehicle charging station, for example, electric vehiclecharging station 12 (shown in FIG. 1) and/or electric vehicle chargingstation 100 (shown in FIG. 2). In the exemplary embodiment, method 552includes storing 554 a plurality of state machines, for example, firststate machine 200 (shown in FIG. 3), second state machine 300 (shown inFIG. 4), third state machine 400 (shown in FIG. 5), and fourth statemachine 500 (shown in FIG. 6). In the exemplary embodiment, the statemachines are stored as firmware within a controller, for example,controller 10 (shown in FIGS. 1 and 2). In the exemplary embodiment,method 552 also includes initializing 556 electric vehicle chargingstation 12 and determining 558 a selected state machine of the pluralityof state machines to apply to electric vehicle charging stationoperation. Furthermore, method 552 includes operating 560 electricvehicle charging station 12 in accordance with the selected statemachine. More specifically, operating 560 includes configuring acharging station controller, for example, controller 10 (shown in FIG.1), to operate charging station 12 in accordance with a state machineassociated with a charging station selection signal.

Controller 10 may determine 558 which of the state machines to applybased on a charging station selection signal associated with one statemachine of the plurality of state machines. The charging stationselection signal may be received from a user, for example, at inputinterface 80 (shown in FIG. 1).

Alternatively, controller 10 may determine 558 which of the statemachines to apply by analyzing devices coupled to the electric vehiclecharging station controller and/or analyzing a configuration of chargingstation controller 10. For example, controller 10 may determine that anRCD, for example, RCD 110 (shown in FIG. 2), is coupled to controller10. Based on this information, controller 10 may determine that a statemachine conforming with IEC specifications should be applied.Alternatively, controller 10 may determine that a ground fault testingdevice, for example, ground fault testing device 66 (shown in FIG. 1) iscoupled to controller 10. Based on this information, controller 10 maydetermine that a state machine conforming with NEMA specificationsshould be applied.

In the exemplary embodiment, method 552 also includes monitoring 562 atleast one condition and transitioning 564 between states included withinthe selected state machine upon satisfaction of the at least onecondition. For a NEMA compliant state machine, for example, statemachines 200 and 400, monitoring 562 may include, but is not limited to,testing for a ground fault condition, monitoring a connection betweencharging station 12 and electric vehicle 22, receiving a charge signalfrom the user, and monitoring a charge level of electric vehicle 22.

In another example, for an IEC compliant state machine, for example,state machines 300 and 500, monitoring 562 may include, but is notlimited to, monitoring a test pilot diode in electric vehicle 22,monitoring a charge level of electric vehicle 22, monitoring fault/alarmconditions, and monitoring a locking mechanism that secures a cable tocharging station 100.

Method 552 may also include displaying 566 information to a user ofcharging station 12, wherein the information is dependent upon a currentstate. For example, a display device, for example, at least one displaydevice 72 (shown in FIG. 1), is configured to display information to auser of charging station 12. Furthermore, method 552 may includereceiving 568 an authorization signal and authenticating the identity ofthe user. For example, a user may provide information to controller 10using an authorization device, for example, authorization device 78(shown in FIG. 1). As an additional example of determining 558 whichstate machine to run, controller 10 may determine that authorizationdevice 78 is coupled to controller 10. Based on this information,controller 10 may determine that a state machine that includes at leastone authorization state, for example, state machines 400 and 500, shouldbe applied.

Described herein are exemplary methods and systems for charging of avehicle that includes an electrochemical energy storage device. Themethods and systems facilitate use of a single electric vehicle chargingstation controller in various models of electric vehicle chargingstation. Such models may be required to adhere to local standards and/orprotocols. The charging station controller is configured to operate inaccordance with a plurality of state machines, wherein each statemachine corresponds to a different model of electric vehicle chargingstation.

The methods and systems described herein facilitate efficient andeconomical charging of an electric vehicle. Exemplary embodiments ofmethods and systems are described and/or illustrated herein in detail.The methods and systems are not limited to the specific embodimentsdescribed herein, but rather, components of each system, as well assteps of each method, may be utilized independently and separately fromother components and steps described herein. Each component, and eachmethod step, can also be used in combination with other componentsand/or method steps.

When introducing elements/components/etc. of the methods and apparatusdescribed and/or illustrated herein, the articles “a”, “an”, “the”, and“said” are intended to mean that there are one or more of theelement(s)/component(s)/etc. The terms “comprising”, “including”, and“having” are intended to be inclusive and mean that there may beadditional element(s)/component(s)/etc. other than the listedelement(s)/component(s)/etc.

This written description uses examples to disclose the invention,including the best mode, and also to enable any person skilled in theart to practice the invention, including making and using any devices orsystems and performing any incorporated methods. The patentable scope ofthe invention is defined by the claims, and may include other examplesthat occur to those skilled in the art. Such other examples are intendedto be within the scope of the claims if they have structural elementsthat do not differ from the literal language of the claims, or if theyinclude equivalent structural elements with insubstantial differencesfrom the literal language of the claims.

1-27. (canceled)
 28. A method for controlling a charging device forcharging an energy storage device, said method comprising: storing aplurality of state machines; and configuring a charging devicecontroller to select a state machine of the plurality of state machinesand to operate the charging device in accordance with the selected statemachine.
 29. A method in accordance with claim 28, further comprisingconfiguring the charging device controller to determine which of theplurality of state machines to select.
 30. A method in accordance withclaim 29, wherein configuring the charging device controller todetermine which of the plurality of state machines to select comprisesconfiguring an input interface to receive a charging device selectionsignal associated with one state machine of the plurality of statemachines.
 31. A method in accordance with claim 29, wherein configuringthe charging device controller to determine which of the plurality ofstate machines to select comprises analyzing a configuration of thecharging device controller.
 32. A method in accordance with claim 28,further comprising configuring a display device to display informationto a user of the charging device.
 33. A method in accordance with claim28, further comprising configuring an authorization device coupled tothe charging device controller to receive an authorization signal fromthe user.
 34. A method in accordance with claim 28, wherein the energystorage device is included within an electric vehicle, and whereinstoring a plurality of state machines includes storing a NationalElectrical Manufacturers Association (NEMA) compliant state machine andan International Electrotechnical Commission (IEC) compliant statemachine.
 35. A method in accordance with claim 34, wherein storing aNEMA compliant state machine comprises, storing a state machineconfigured to test for a ground fault condition, monitor a connectionbetween the charging device and the electric vehicle, and discontinuecharging of the electric vehicle upon occurrence of a fault.
 36. Amethod in accordance with claim 34, wherein storing an IEC compliantstate machine comprises, storing a state machine configured to lock aconnection device to the charging device, monitor a pilot diode in theelectric vehicle, discontinue charging of the electric vehicle uponoccurrence of a fault, and unlock the connection device from thecharging device.
 37. A method for charging an energy storage device,said method comprising: storing a plurality of state machines;configuring a charging device controller to select a state machine ofthe plurality of state machines; and configuring a charging devicecontroller to charge the energy storage device in accordance with theselected state machine.
 38. A method in accordance with claim 37,wherein each state machine is configured to provide entry actions andexit actions associated with each state.
 39. A method in accordance withclaim 37, wherein each state machine is configured to provide waitingactions that are executed while waiting to transition our of the state.40. A method in accordance with claim 37, wherein said charging deviceincludes an input interface configured to receive a state machineselection signal.
 41. A method in accordance with claim 37, furthercomprising configuring the charging device controller to operate inaccordance with a predetermined state machine.
 42. A method inaccordance with claim 41, wherein the predetermined state machine isconfigured to be selected by a technician upon installation of thecharging device.
 43. A method in accordance with claim 41, wherein thepredetermined state machine is configured to be selected by aconfiguration server coupled to the charging device.
 44. A method inaccordance with claim 37, further comprising updating the storedplurality of state machines to configure the plurality of state machineswith new or edited states.
 45. A method in accordance with claim 38,wherein said entry actions comprise requesting authorization from asmart meter connected to the charging device.
 46. A method in accordancewith claim 38, wherein said entry actions comprise updating a userdisplay based on the current state.
 47. A method in accordance withclaim 39, wherein said waiting actions comprise waiting for a smartmeter connected to the charging device to provide an authorization toproceed with charging.